I read somewhere in the forum about using two subs and connecting them to the rear surrounds for full range sound in addition to the main subwoofer for all channels.

I have large front and center speakers that I would consider a crossover point of 60hz for argument sake. Below 60 hz would be routed to the front subwoofer.

For the rear surrounds the same might apply above 60 hz to the two subs and satellites in the rear surround, below 60 hz to the main front sub.

Question is how would I make the connection to include these rear subs to work in conjunction with the rear surround speakers firstly and the system as a whole second?
What setting if any would the rear sub X over be set at? What about the X over points on the pre/pro?

I suppose maybe the subs would be connected first from the rear amp and then wired from the subs to the rear surrounds?

I think it would be interesting to try anyway. If anyone has input on this or the link I am speaking of please send it.